Wireless-Fidelity (Wi-Fi) is a technology that can connect clients such as a personal computer and a hand-held device wirelessly, where the clients can communicate with each other by using an access point, and meanwhile, the access point can provide management and a service for the clients. As a coverage range of the Wi-Fi access point is increasingly wide, there are more and more indoor positioning systems implementing indoor positioning by using Wi-Fi. For example, when people in an unfamiliar shopping mall want to know in which positions of the shopping mall they are located, or need to determine their positions when searching for a certain destination by means of indoor navigation, they can determine their positions by using their Wi-Fi-enabled mobile phones.
However, when users want to determine their positions, unstable signal intensity and a measurement error produced by multipath and wall penetration during communication leads to inaccurate positioning and inconvenience of use of a positioning function, which prevents the users from learning their positions accurately.